Abba ben Joseph bar Ḥama (c. 280 – 352 CE), who is exclusively referred to in the Talmud by the name Rava (רבא), was a fourth-generation rabbi (amora) who lived in Mahoza, a suburb of Ctesiphon, the capital of Babylonia. He is one of the most often-cited rabbis in the Talmud. He studied at the Talmudical Academy at Pumbedita, site of modern-day Falluja, Iraq. There he, traditionally, became famous for his debates with his study-partner Abaye. The debates between Abba ben Joseph and Abaye are considered classic examples of Talmudic dialectical logic. Of their hundreds of recorded disputes, the law is decided according to the opinion of Abba ben Joseph in all but six cases. His methodology greatly influenced not only his students, but the stammaim, as well.[1]

Rava married the daughter of third-generation amora Rav Hisda after she'd been widowed from Rami bar Chama. In TB Bava Batra 12b, Rav Hisda's daughter is sitting in her father's classroom, while his students, Rava and Rami bar Chama, stand before them. When Rav Hisda asks her which of the two she wants to marry, she replies "both of them," and Rava adds, "I'll be the last one" (commentators let us know that she indeed married Rami first and Rava second). They had five sons, the eldest of whom, Joseph, died during his parents' lifetime.

When Rabbah bar Nahmani, the head of the yeshiva of Pumbedita, retired, the position went to Abaye. At that point, Abba ben Joseph returned to Mahoza, in Babylonia, where he established a yeshiva there. After the death of Abaye, many of his students moved from Pumbedita to Mahoza, to join Abba ben Joseph's Yeshiva, which had become one of the intellectual centers of the Babylonian Jewish Community. Rava died ca 355.

Rava apparently had to reply to a deep-seated skepticism toward rabbinic authority and to defend the authenticity of the rabbinic oral tradition. The skepticism of Mahozan Jewry was fueled in part by the acceptance of the Manichaean polemic against Zoroastrianism and its insistence on oral transmission, and by a strong concern with the problem of theodicy, encouraged by a familiarity with Zoroastrian theology. Rava’s creativity was fueled by his cosmopolitan urban environment. For instance, he ruled that one who habitually ate certain non-kosher foods because he liked the taste was nevertheless trustworthy as a witness in cases involving civil matters. So too did he suggest that a lost object belongs to the person who discovers it even before the loser is aware of his loss, because it prevented the loser from resorting to urban courts to try to get his property back and eliminated the period of uncertainty of possession. It also led to the legal concept that 'future [psychological] abandonment [of possession] when unaware [of the loss] is [nevertheless retrospectively accounted] as abandonment'. Ultimately, Rava’s views were decisive in shaping the Bavli’s approach to the problem of theodicy, legal midrash, and conceptualization, all of which stand in stark contrast to the Yerushalmi."[2]